The home of the polar bear is under threat because hot summers are making the ice it lives on melt.
A new study has found that summers in the arctic are getting longer, thinning the ice that polar bears use to hunt the seals that they eat.
A different study showed ice there has thinned by 40% in the last 40 years.
The problem may make global warming worse because ice reflects sunlight away from the earth, and without the ice it may stay here and get warmer.